1. Field of the Invention
The present invention relates to tillage tools and more particularly to a new wavy disc and coulter.
2. Background of the Invention
Wavy coulters are presently used ahead of no-till implements, such as a planter, to fracture a narrow band of soil to prepare the soil to receive the no-till implement, for example as shown in U.S. Pat. No. 5,473,999 to Rawson, which is incorporated herein by reference in its entirety. The coulters are set at a penetrating depth of about four inches, and the amplitude of the wave from crest-to-valley is about one to two inches and generally defines the width of the band. All crests and all valleys deviate from a single plane by the same amount. These traditional wavy coulters are designed for only one speed, and if they go faster they throw great amounts of dirt.
The crests and valleys on presently available wavy coulters are positioned to extend out from the center of the coulter in a line generally coincident with the radius of the coulter. As each wave enters the soil, the line of the wave enters the soil at an angle with respect to vertical.
A wavy coulter was disclosed in U.S. Pat. No. 5,649,602, which patent is incorporated herein by reference in its entirety. In U.S. Pat. No. 5,649,602, the waves of the coulter extend back from the peripheral edge of the coulter in respective adjacent lines disposed at a predetermined acute angle with respect to the radius of the coulter body. The maximum amplitudes of all the periodic deviations from flat are equal. It has been shown, however, that varying the maximum amplitudes of the periodic deviations from flat provides advantages over this prior art.
Herein, deviation from flat is defined by a distance from a plane in which the periphery of a flat coulter resides.
Discs are similar to coulters except they have a convex shape on one side and a concave shape on the other side thereof for the purpose of throwing dirt in a direction from the convex to the concave side. Discs usually do not have a wavy configuration but often do have notches formed in the outer periphery thereof, for example like U.S. Pat. No. 6,554,079 to Bruce and the prior art shown therein, all of which are incorporated herein by reference in their entirety.